question on fixing the mpz_sizeinbase() command to work correctly

[Paul Zimmermann]

> > I am examining thousands of different numbers, maybe more.
> >
> Then it's more efficient to implement the final check on your side, keeping the already computed powers and reusing them.

indeed it will be much more efficient:

0) for each value k returned by mpz_sizeinbase in your application range,
   store the threshold value BASE^(k-1)

1) for each input n, let k = mpz_sizeinbase (n, BASE)

2) if n >= BASE^(k-1), return k, else return k-1

Step 0 is a precomputation and has only to be done once.

Paul Zimmermann